1. Field of the Invention
This invention relates to optical disc apparatuses and, more particularly, to an optical disc apparatus which is adapted to discriminate the kind of a disc depending upon the level of a reproduced signal outputted, for example, from an RF amplifier.
2. Prior Art
In the conventional optical disc apparatuses of this kind, the reproduced signal is adjusted to a constant level by an AGC (Automatic Gain Control) circuit of an RF amplifier so that the signals recorded on the disc can be reproduced in accordance with a disc type.
In such prior art apparatuses, however, because the reproduced signal level is constantly adjusted by an AGC circuit, the normal disc (CD-ROM) and the rewritable disc (CD-RW) have respective RFDC signals generally at the same level. Accordingly, the discrimination on the disc type is impossible based on the reproduced signal outputted from the RF amplifier. This raises a problem that, if the disc type is incorrectly discriminated, the reproduced signal possibly exceeds a dynamic range of the AGC circuit as a result of a significant difference, between CD-ROM and CD-RW, in the reproduced signal level by the RF amplifier.